Resolution prediction for bandpass-sigma-delta-modulators using SIMULINK behavior simulation

This paper presents a detailed survey of the impact of circuit non-idealities of bandpass sigma-delta modulators (BP-SDM) affecting the signal-to-noise and distortion ratio (SNDR) and therefor the resolution. The presented results have been developed using SIMULINK behavior simulations of a second order BP-SDM. A behavior simulation has the advantage of a fast simulation of any BP-SDM structure and provides a deeper understanding of the influence on the SNDR. The determined parameters are the sampling jitter Delta T, the sampling or kT/Cnoise, and the OTA non-idealities finite DC gain Av0, gainbandwidth GBW, slew-rate SR, and OTA-noise Vn,OTA, which are relevant in a switched capacitor realization of the BP-SDM. The simulated results are compared to theoretical values using transfer functions.